function x = lpc2mat(y,f)
error(nargchk(1,2,nargin));
if nargin < 2
    f = 1;
end
f = f(end:-1:1);
[m,n] = size(y);
order = length(f);
f = repmat(f,m,1);
x = zeros(m,n+order);
for j = 1:n
    jj = j + order;
    x(:,jj) = y(:,j) + round(sum(f(:,order:-1:1) .* x(:,(jj-1):-1:(jj-order)),2));
end
x = x(:,order + 1:end);
end
